Rotary vane fluid power unit



June 28, 1966 c. E. ADAMS ETAL ROTARY VANE FLUID POWER UNIT 4Sheets-Sheet 1 Original Filed Sept. 14, 1962 FIG. I

FIG. 6

INVENTOR. CECIL E. ADAMS JOHN F. HEDGE FIG. 5

OLSON TREXLER WOLTERS 8 BUSHNELL June 28, 1966 c. E. ADAMS ETAL3,257,958

ROTARY VANE FLUID POWER UNI'II Original Filed Sept. 14, 1962 4Sheets-Sheet 2 WOLTERS 8| BUSHNELL June 28, 1966 c; E. ADAMS ETAL3,257,958

ROTARY VANE FLUID POWER UNIT Original Filed Sept. 14, 1962 4Sheets-Sheet s asa "2a l li iu- INVENTORS. CECIL E. ADAMS JOHN F. HEDGEOLSON, TREXLER WOLTERS 8| BUSHNELL June 28, 1966 c. E. ADAMS ETAL3,257,958

ROTARY VANE FLUID POWER UNIT Original Filed Sept. 14, 1962 4Sheets-Sheet 4 I04 INVENTORS.

CECIL E. A

FIG. I5 JOHN F. 0

BY oz.so-, TREXLER WOLTERS a BUSHNELL United States Patent ()1 3,257,958Patented June 28, 1966 ice ' 3,257,958 ROTARY VANE FLUID POWER UNITCecil E. Adams, Columbus, and John F. Hedge, Worthington, Ohio,assignors to American Brake Shoe Company, New York, N.Y., a corporationof Delaware Continuation of application Ser. No. 223,748, Sept. 14,

1962. This application Mar. 29, 1965, Ser. No. 445,855

26 Claims. (Cl. 103-136) The present application is a continuation ofapplicants copending application Serial No. 223,748, filed September 14,1962, now abandoned.

The present invention relates to rotary vane pumps and motors, which forconvenience will be referred to generally as rotary vane fluid powerunits. A fluid power unit of this character is disclosed in UnitedStates Patent No. 2,832,293, issued April 29, 1958, to one of theapplicants of the present application and Yung Ho Sun.

As compared to other types of pumps and motors, rotary vane pumps andmotors characteristically afford advantages including relativelylow-initial cost of manufacture and relatively small physical size.However, the performance capabilities now being sought from vane pumpsand motors have greatly increased the significance of limitations andshortcomings inherent in conventional pumps and motors of this type. Thecapabilities being sought in rotary vane fluid power units includelengthened durability or service life,'capacity to work efliciently anddependably against very high fluid pressures, and the capability ofoperating efficiently and dependably over a widespread speed rangeincluding very high operating speeds.

One object of the invention is to provide a rotary vane fluid power unithaving a new and improved construction which materially increases theperformance capabilities of the unit, while at the same time minimizingthe physical size of the unit.

Another object is to provide an improved rotary vane fluid power unithaving a novel construction which minimizes to advantage the size of theunit, while at the same time providing an advantageous capability oftheunit to operate against very high fluid pressures with efficiency anddependability over a long service life of the unit.

Another object is to provide a rotary vane fluid power unit in whicheffective sealing engagement of the vanes with a coacting cam surface isobtained by a new and improved construction which assures that each vaneis continuously urged outwardly by a force that is effective, yet notexcessive.

Another object is to provide a rotary vane fluid power unit having animproved construction which assures that each vane is continuously urgedoutwardly, while at the same time serving during operation of the unit-to effect through fluid pressure a cyclic increase in the outward forceon the vane, which cyclic increase in force is automaticallysynchronized to advantage with progress of the vane along a coacting camsurface.

Another object is to provide a rotary vane power unit of the abovecharacter in which high performance capabilities are achieved in a unitof significantly minimized size by virtue of an improved constructionwhich at once (1) effects an application to each vane by fluid pressureof a highly advantageous outward force, (2) provides to eacn vane veryextensive support from a rotor of minimized size, and (3) produces greatstrength in the vane supporting rotor structure, while at the same timeeffectively minimizing the size of the rotor.

Another object is to provide an improved rotary vane fluid power unit inwhich the vanes are forced outwardly by fluid pressure energizedstructure which affords a highly advantageous mutual reinforcement ofportions of the rotor which slidably support the vane.

Another object is to provide an improved rotary vane fluid power unit inwhich the vanes are urged toward a 5 coacting cam surface to greatadvantage by the cumulative action of springs and the forces of fluidpressure.

Another object is to provide a rotary vane pump in which the outwardforce, which must be applied to individual vanes moving through a fluidintake zone in the pump in order to maintain engagement of the vaneswith ,the coacting cam surface when the pump is operated at high speeds,is minimized to great advantage by an improved shaping of the vane slotsand vanes that materially accelerates the flow of incoming fluid intothe inner portions of the vane slots while at the same timeadvantageously minimizing the size of the fluid flow passages requiredwithin the pump rotor for supplying fluid to the inner portions of theslots.

Another object is to provide a rotary vane pump having high speedoperational capabilities that are materially enhanced by virtue of animproved shaping of the vanes which in effect serves to centrifugallypump incoming fluid into the vane slots inwardly of the vanes as thevanes move outwardly in passing through a fluid intake zone in the pump.

Another object is to provide a rotary vane fluid power unit in whichmaintenance of optimum pressure contact with the coacting cam surface ortrack of vanes moving through and beyond a fluid discharge zone in theunit is aided to great advantage by an improved control of the dischargeof fluid from the vane slots.

Another object is to provide a rotary vane fluid power unit in which animproved control of the discharge of fluid from the vane slots isprovided and utilized to achieve at once a highly advantageous reductionof fluid resistance to inward acceleration and inward movement of vanesmoving through a fluid discharge zone within the unit and an equallyadvantageous deceleration by fluid of inwardly motion of vanes passingfrom the fluid discharge zone to an adjacent sealing zone within theunit.

Another object is to provide an improved rotary vane fluid power unit asrecited in the preceding object in which the reduction of fluidresistance to inward movement of the vanes is coordinated with therotary motion of thevanes to maintain optimum pressure contact with thecam surface of vanes entering into a fluid discharge zone within theunit.

Another object is to provide a rotary vane fluid power unit or' pump ofthe character recited in the preceding objects which is capable ofserving as either a pump or a motor.

Another object is to provide a rotary vane fluid power unit of thecharacter recited in the preceding objects, which is inherently welladapted for economical manufacture.

Other objects and advantages will become apparent from the followingdescription of the exemplary embodiments of the invention illustrated inthe accompanying drawings, in which:

FIGURE 1 is an axial sectional view of a rotary vane fluid power unitembodying the invention;

FIG. 2 is a transverse sectional view, taken along the line 2-2 of FIG.1, and showing the cam ring, a segment of the housing and the highpressure porting in the latter rotated ninety degrees;

FIG. 3 is an axial sectional view, taken. along the line I s s of 1FIG.2; a

FIG. 4 is a face view of the pressure or cheek plate,

FIG. 6 is a perspective view on an enlarged scale of a vane actuatingrotor reinforcing element associated with each vane;

FIG. 7 is a fragmentary sectional view taken along the arcuate line 7--7of FIG. 2 and showing fluid supply passages in the rotor for energizingfluid actuating elements for the respective vanes;

FIG. 8 is a sectional view taken along the line 88 of FIG. 1 and showingvalve means used to supply operating fluid to the fluid actuatingelements for the vanes from the connecting passage under a higher fl-uidpressure;

FIG. 9 is an axial sectional view similar to the central portion of FIG.1 but showing a modified construction of the unit;

FIG. 10 is a fragmentary sectional view taken along the line 1010 ofFIG. 9;

FIG. ll is a fragmentary sectional view on an enlarged scale taken withreference to the line 1111 of FIG. 2, but showing a slight modificationof the structure used in the unit of FIGS. 1 to 8;

FIG. 12 is a fragmentary sectional view taken along the line 1212 ofFIG. 11;

FIG. 13 is a fragmentary sectional view taken with reference to the line1313 of FIG. 1 but illustrating in phantom the relationship of one endof a typical vane and vane slot to adjacent outlet port structure as thevane moves into one fluid discharge zone;

FIG. 14 is a view similar to FIG. 13 but illustrating a later phase inthe movement of the vane and slot through the fluid discharge zone inwhich the inner portion of the slot is fully alined with the adjacentport structure; and

FIG. 15 is a view similar to FIG. 14 but illustrating a still laterphase in the progress of the vane and slot through the fluid dischargezone in which the inner portion of the slot is displaced beyond theadjacent port structure.

Referring to the drawings in greater detail, the pump forming theembodiment of the invention illustrated in FIGS. 1 to 8 comprises arotor 22 encased within a pump housing 24 which includes, as shown, acam ring 26 encircling the rotor. The inner periphery of the cam ring 26defines a cam surface 28 encircling the periphery 30 of the rotor, andbeing shaped and positioned to define with the outer periphery of therotor two arcuate spaces 32 for fluid located generally on diametricallyopposite sides of the rotor, FIG. 2.

The two opposed spaces 32 constitute in the pump 20 pumping spaces forfluid. The two spaces 32 are not necessarily discontinuous, since thespace between the cam surface 28 and the rotor periphery 30 extends allthe way around the rotor. However, the spacing between the cam surface28 and the rotor periphery 3t) narrows between the two pumping spaces 32to the extent that these spaces may here be regarded as beingdiscontinuous.

it will be understood that the pump 20 is a balanced pump and that theforces on the rotor of fluid under pressure within the opposed spaces 32are largely balanced.

The rotor 22 is supported and driven by a splined drive shaft 34journalled in the housing 24. As shown best in FIG. 1, opposite ends ofthe rotor 22 define and "are bounded by two flat end faces or surfaces35, 37.

intake or suction end of each of the pumping spaces 32 (thecounterclockwise end as viewed in FIG. 2) is connected to an inlet orsuction passageway 46 formed in the section 48 of the pump housing 24.As shown in FIGS. 1, 2 and 3, the intake passageway 46 connects with twoannular passages 50 formed in the housing 24 in generally encirclingrelation to the cam ring 26. The two passages 50 communicatecontinuously with the intake end of each pumping space 32 through twointake ports 52, 54 formed in the housing section 38 and cheek plate 42for each space 32, as shown in FIG. 3, and communicating at opposite endof the rotor with the intake end of the adjacent pumping space 32.

The opposite or discharge ends of the pumping spaces 32 (the clockwiseends with reference to FIG. 2) are connected continuously to an outletor discharge passageway 56 formed in the housing section 38, FIG. 1. Asshown the outlet passageway 56 communicates with the outlet ends of thepumping or working spaces .32 through ports 53 opening through the rotorconfronting face 36 in the housing section 38, FIG. 1, incircumferentially spaced relation to the intake ports 52 and 54communicating with the inlet ends of the spaces 32, FIGS. 2 and 3.

The rotor 22 carries an annular series of vane units 6t FXGS. l, 2 and5, which operate upon rotation of the rotor to move fluid through eachof the pumping spaces 32 from the associated intake ports 52, 54 to thecoacting discharge port 58.

Each vane unittl comprises a flat vane 62 slidably disposed within acoacting slot 64 in the rotor 22. Each slot 64 extends between oppositeends of the rotor 22 and opens outwardly through the periphery of therotor to allow the coacting vane 62 to project outwardly into slidingengagement with the cam surface 28.

As shown, the outer end of each vane 62 defines two spaced paralleledges 66, 68, one or both of which are caused to continuously engage thecam surface 28. The outer end of each vane is subject to exposure to thepressure of fluid in the interspace adjacent the vane between theperiphery of the rotor and the encircling cam surface 28. In thisinstance, the outer end of each vane '62 defines a surface 76) locatedbetween the sealing edges 66 and 68. The force of fluid pressure on thesurface 70 tends to urge the vane inwardly. As shown, the surface 70 onthe outer end of each vane is recessed inwardly of the adjacent sealingedges 66, 68 to define a groove 72 extending the full axial length ofthe vane.

Effective sealing engagement of each vane 62 with the cam surface 28 isassured continuously by the cumulative action on the vane of the outwardforce of fluid pressure on the inner edge of the vane, the outward forceof spring pressure applied to the vane, and the outward force of fluidunder a high pressure continuously applied to a high pressure vanebiasing area associated with each vane and isolated from directcommunication with the inner edge of thevane, as will be described.Moreover, each vane unit 66 has a construction which provides thedesired outward biasing forces for a coacting vane, while at the sametime providing extensive and highly efficient support to the vane andaffording a highly effective reinforcement of the rotor structure whichsupports the vane.

As shown in FIGS. 1 and 5, the inner edge of each vane defines a secondbiasing surface 74 extending across the full axial length of the vane.Fluid pressure applied to the surface 74 acts to urge the vaneoutwardly, as previously intimated.

The space between the inner edge surface 74 of each vane and the bottomof the coacting vane slot 64 is continuously connected to communicatewith the first surface 78 on the outer edge of the vane. The two ends ofeach vane 62 at the ends of the rotor 22 are medially grooved to definemedial channels 76 connecting opposite ends of the outer vane groove 72with the inner vane surface 74. Also, two spaced parallel bores 78 aremachined the opposing sides of the coacting slot.

in' each vane 62 to extend inwardly through the vane from the outergroove 72 to the inner surface74.

The third force of fluid pressure acting on each vane is produced bystructure which extends outwardly in thecoacting vane slot an extensivedistance outwardly beyond the inner extremity of the vane.

As shown in FIGS. 2, 3 and 5, each vane is shaped to define a centralnotch 82 of substantial width extending bet-Ween opposite sides of thevane and extending outwardly from the inner extremity of the vane for avery substantial distance. As illustrated, each notch 82 has a radialdepth, measured from the inner extremity of the vane to the bottom ofthe notch, which is somewhat greater than one-half the correspondingtotal radial dimension of the vane from the inner to the outer radialextremities of the vane. Also, each vane notch 82 has substantial widthmeasured axially with respect to the rotor.

Each vane notch 82 accommodates a central plug 84 which is machinedseparately from the rotor 22. A typical plug 84 is illustrated inperspective in FIG. 6, and has a form which is adapted to bemanufactured economically with precision.

As shown, each plug 84 has a relatively Wide outer portion 86 adapted tofit firmly within the coacting slot 64 and provide mutual reinforcementto adjacent portions of the rotor defining opposite sides of the slot.The two opposite rotor engaging faces 88, FIG. 6, of the plug segment orportion 86 are designed to fit firmly against Preferably, a medial,generally radial groove 90 is formed in each face 88 of each plug tofacilitate insertion of the plug into a coacting vane slot in the rotor.This construction of the plugs makes for economy of manufacture while atthe same time affording a close fitting relationship of the plugs androtor so that optimum reinforcement is provided to the rotor by theplugs.

The inner end of each plug 84 defines a cylindrical projection 92designed to fit into a cylindrical bore 94 extending into the rotor 22from the bottom of the coacting slot 64, as shown in FIGS. 1, 2 and 3.

Each plug 84 is centrally bored longitudinally from the outer end of theplug to define an outwardly open cylinder 96, FIG. 5, which stops shortof the extreme inner end of the plug. The cylinder 96 receives a freelymovable yet close fitting plunger 98 having a tapered outer endextending beyond the plug and adapted to engage the inner edge of thecoacting vane 62 at the bottom of the notch 82.

A transverse bore 100 formed in the cylindrical projection 92 of eachplug 84 intersects the plug cylinder 96 inwardly of the plunger 98 andconnects with an oblique bore 102 formed in the rotor 22 and extendingbetween opposite end faces of the rotor at an angle to the axis of therotor, as illustrated in FIGS. 1, 5 and 7. An annular series of bores102 are drilled in the rotor 22 inwardly of the slots 64 for feedinghigh pressure fluid to the cylinders in the respective plugs.

Opposite ends of the high pressure bores 102 continuously communicatewith annular grooves 104, 106

formed in the opposing. faces of the housing section 38 and cheek plate42.

The annular groove 106 in the cheek plate 42 is connected through bores108, FIG. 1, with an annular pressure space 110 defined between the endof the cheek plate 42 opposite from the rotor 22 and the housing section38. The annular pressure space 110 is continuously connected with thehigh pressure end of one of the of the bore 116. Opposite ends of thebore 116 are stoppered by threaded plugs 120. A port 122 in the plate 42connects one end of the bore 116 with an intake port 54, FIGS. 3 and 9,for the working space 32 which supplies fluid to the pressure space 110.The other end of the same working space 32 is connected through apassage 124 in the cheek plate 42, FIG. 1, and a bore 126 with the endof the bore 116 opposite the bore 122.

Two flatted enlargements 128 on the spool 114 engage the bore 116 toguide the spool. A central enlargement 130 on the spool 114 slidablyengages the bore 116 and forms a seal between the bores 122, 126,whereby the spool 114 automatically moves to the low pressure end of thebore 116 to connect the pressure space 110 with p the high pressure endof the bore 116 and hence with the high pressure end of the connectedworking space 32.

This construction provides an extended versatility in the.use of theillustrated pump 20, in that the pump can be reversed, if so desired, toreceive fluid through the passageway 56, and to discharge fluid throughthe passit acts to urge the pressure or cheek plate 42axiallyagainst-the rotor 22. This same high pressure fluid is.

connected through the bores 108, 102 and 100 to the inner ends of theplug cylinders 96, as described, where this high pressure fluid acts onthe inner end of each plunger 98 to urge the coacting vane 62 outwardly,as described. Thus, the inner end of each plunger 98 defines a thirdsurface 132 on which high pressure fluid acts to urge the coacting vaneoutwardly.

As shown, outward spring force is continuously applied to each vane 62by two helical compression springs 134, 136 disposed on opposite sidesof the intervening plug 84, as shown in FIGS. 1, 3 and 5. .The springs134, 136 for each vane have outer, power applying ends 135, 137extending into counterbores 138, 140 in the vane bores 78, FIG. 5. Thesprings 134, 136 are smaller in diameter than the counterbores 138, 140and the power applying ends 135, 137 of the springs press-against theouter ends of the counterbores 138, 140 for movement in and out with thevane. The inner ends 139, 141 of the springs 134, 1 36 rest on seats142, 144 in shallow bores 146, 148 extending into the rotor 22from thebottom of the coacting vane slot 64. Thus, the inner or support ends139, 141 of the springs 134, 136 are stationary with respect to therotor 22 with the result that the springs are flexed and store energy'upon inward movement of the vane and subsequently release energy byrelaxation to extend the vane.

All the forces applied to each vane 62 and tending to move the vanewithin the rotor slot operate cumulatively to assure continuous andeffective engagement of the vane with the cam surface 28 under alloperating conditions. In this connection it should be borne in mind thatthe outward force required to keep each vane in optimum engagement withthe cam surface 28 varies as the vane progresses through its annularpath or orbit.-

As each vane 62 moves through the fluid intake end or zone 150 of eachpumping space 32 the vane must move outwardly in its slot to maintainits contact with the cam surface. (For convenience in identification,the successive zones including the intake zones 150 within the pumpthrough which a vane passes are denoted in FIG. 2 by the correspondingradial angles of the annular path of the vane.) Moreover, each vane mustbe moved radially outward in each intake zone at a speed that iscommensurate with the rotary speed of the rotor. The force required toaccelerate each vane radially outward sufliciently to maintain the vanein contact with the cam 7 surface as the vane moves through each intakezone increases as an exponential function of the rotary speed of therotor 22 and for this reason can become very high as rotor speeds areincreased to increase the output volume that can be obtained from a pumpof any particular size.

In the pump described, the plunger 8 coacting with each vane providesfor forcing the vane outwardly with in each intake zone 156 a forcewhich is very powerful in relation to the transverse area of the plungerby virtue of the fact that the inner end surface 132 of the plunger iscontinuously subjected to the high output pressure of the pump and theouter end of the plunger and the outer edge of the vane are exposed tothe much lower pressure of fluid entering the intake zone. Thus, .in thepump, each vane plunger 98 can make available for extending the coactingvane in an intake zone 150 a force which is far greater than the vaneextending force that can be provided by a spring that can beaccommodated within a similar space in the pump rotor. Moreover, theoutward force of each plunger 98 does not decrease as the coacting vanemoves outwardly. Consequently, the pump can be driven at high speeds toobtain high output capacity with assurance that vanes passing throughthe intake zones 150 are held in contact with the cam surface 28 byapplied forces including those applied by the plungers 98.

As previously intimated, the construction of the pump serves not. onlyto maximize the elftctive output capacity of the pump, but also tominimize the size of the pump. In this connection, it is especiallynoteworthy that the structure which defines the plunger cylinders 96extends radially out into the vane slots 64 a very substantial distanceradially beyond the inner extremities of the slots and a substantialdistance radially beyond the inner positions of the inner extremities ofthe vanes. Moreover, the plunger cylinder defining structure, i.e., theplugs 84 in the pump described; transmits forces between adjacent rotorsectors 151 intervening between and defining the rotor slots 64 to theend that these rotor sectors mutually reinforce each. other insustaining the reaction of the vanes on the rotor sectors. The reactionon each rotor sector 151 of the adjacent vanes changes as the vanesprogress through their orbit. The strength which each rotor sector musthave to withstand the reactions of the adjacent vanes is sharply reducedby the mutual reinforcement of the rotor sectors all of which are notloaded to the same degree at once.

As a consequence, the root diameter of the vane slots 64 can be markedlyreduced. This permits a similar reduction in the overall diameter of therotor without reducing the radial depth of the vane slots. This resultsin a very significant reduction in the overall size of the pump, whileat the same time providing vane slots of extensive overall radial depthwhich accommodate vanes 62 that have overall radial dimensionssufiicient to enable the vanes to project individually a very extensivedistance beyond the rotor, while at the same time providing optimumsupport to the vanes against high fluid pressures. The fact that themedial inner portions of the vanes 62 are cut away to accommodate theplunger cylinder defining structure which provides the desiredreinforcement of the rotor sectors 151 does not significantly weaken thevanes or materially reduce the support provided to the vanes, since theoverall radial dimensions of the vanes are not reduced.

Having reference to the construction of the rotor 22 as illustrated inthe drawings, it will be appreciated that the construction of the rotoritself, apart from the reinforcing plugs 84, is designed to maximize thebending strength of the individual rotor sectors 151 intervening betweenthe vane slots 64. Except as they are mutually reinforced by theintervening plugs 34, the individual rotor sectors 151 have thestructural form of cantilevering arms circumferentially-spaced apart.The forces applied by the vanes 62 to the rotor sectors 151 aresustained by the bending strength of the sectors 151. In keeping withestablished design principles used in the construction of high pressure,high performance vane pumps, the rotor sectors 151 intervening betweenthe vane slots 64 are designed and constructed as illustrated in thedrawings to maximize the bending strength of the rotor sectors. In thisconnection it is noteworthy that the forces transmitted by the vanes 62to the rotor sectors 151 produce in the rotor sectors 151 bendingmoments that tend to increase toward the inner or base ends of the rotorsectors. Moreover the circumferential width of each rotor sector 151decreases in an inward direction on account of the inwardly convergingorientation of the slots 64. Consequently the applied bending stress onthe rotor sectors 151 tends to increase in an inward direction.

The rotor sectors 151 constructed as shown in the drawings are designedto provide within the axial limits of the rotor 22 and within thecircumferential width limitations on the rot-or sectors 151, themaxim-um effective bending strength for the rotor sectors 151.

As shown in the drawings, FIGS. 1 and 5, opposite :axial ends of eachrotor sectors 151 are flush with the fiat rotor end faces 35, 37 andform portions of the end faces 35, 37. Each individual vane 62 has anaxial length equal to the axial spacing between the rotor end faces 35,37 and is flush at its axial ends with the rotor faces 35, 37.

It will be evident from the foregoing observations that the bendingstress on the individual rotor sectors 151 is greatest on the innerportions of the rotor sectors, particularly on the portions 153, FIG. 3,of the rotor sectors 151 that extend inwardly from the radial positionsoccupied by the inner edges 74 of the two adjacent vanes 62 w en thevanes are fully extended. Having reference again to the drawings, itwill be noted that each rot-or sector portion 153 has a minimum axialwidth that is at least substantially equal to the maximum axial width ofthe portion of each adjacent vane 62 that extends outwardly from theperiphery of the rotor when the vane is fully extended, the flat endfaces 35, 37 of the rotor extending across opposite ends of each rotorsector portion 153 and being flush with opposite ends of each adjacentvane 62. Moreover, the portion 153 of each rotor sector 151 locatedradially inward of the radial positions of the inner edges 74 of thefully extended adjacent vanes is of solid construction, as shown, thatis impervious to the passage of fluid therethrough between the adjacentslots 64. The solid construction of the rotor sector portions 153,extending the full axial width of the portions of the vanes 62 thatproject from the periphery of the rotor, serves to maximize the bendingstrength of the rotor sectors 151 while at the same time beingimpervious to the passage of fluid through the rotor sector portions 153between the adjacent slots 64.

It is noteworthy at this point that rounding out of the bottoms of thevane slots 62 to form at the bottoms of the vane slots the transverselyextending concave surfaces 155, identified in FIG. 5, increases thebending strength of the rotor sectors 151 by avoiding stressconcentrations at the bottoms of the slots.

The mutual reinforcement of the rotor sectors 151 gamed by means of theintervening plugs 84 as described magnifies the inherent strength of therotor sectors, solidly constructed as illustrated, to provide thepowerful resistance to deflection of the rotor sectors that permitsminimization of the size of the rotor 22 and radial deepening of thevane slots 64 to maximize the performance to size relationship of theunit as previously indicated.

The two compression springs 134, 136 associated with each vane 62 applycontinuous outward forces to the vane which act cumulatively with theoutward force of the associated vane plunger 98 to move the vaneoutwardly in-continuous contact with the cam surface 28 as the vanepasses through each fluid intake zone 150 as described. However, theforces of the springs 134, 136 on each vane are not necessarilysuflicient of themselves to maintain engagement of the vane with the camsurface 28 When the pump is operated at very high pressures.

The two springs 134, 136 and the high pressure plunger 98 associatedwith each vane 62 continue to act cumulatively to urge the vaneoutwardly into effective sealing engagement with the cam surface 28 asthe vane passes from each fluid inlet zone 150 through a fluid transferzone 152, FIG. 2, to the adjacent fluid outlet zone '154.

While the description of the forces acting on the vanes moving throughthe fluid intake zones 150 and the fluid transfer zones 152 has beenfocused on the outward forces applied to each vane by the coactingsprings 134, 136 and the coacting high pressure plunger 98, it isnecessary I to bear in mind that these are not the only forces actingradially on the vanes. As previously intimated, each vane iscontinuously subjected to the outward force of fluid pressure acting onthe inner edge surface 74 of the vane and to the inward force ofpressure acting on the outer edge surface 70 of the vane. In a generalway, the inward and outward forces of fluid pressure acting on the vanesurfaces 78 and 74 offset each other; This follows from the fact thatthe inner edge surface 74 of each vane is continuously connected withthe outer edge surface 70 of the vane through the end grooves 76 and thebores 78 formed in each vane as described.

However, the effective area of the outer edge surface 70 of each vane,which is continuously connected with the inner edge surface 74, is notnecessarily precisely equal to the effective area of the inner surface74 because of the formation on the outer edge of the vane of the twonarrow sealing edges 66, 68. Yet, for the purpose of understanding thepresent invention, the effective area of the outer edge surface 70 ofeach vane may be regarded as being the same as that of the inner edgesurface 74 of the vane, so that the forces of equal fluid pressure onthe two opposed surfaces 70, 74 are substantially balanced.

Also, it may be observed, with reference to FIGS. and 6, that the outerend 153 of each high pressure Vane actuating plunger 98 is pointedsomewhat in the form of a truncated cone to localize the engagement ofthe plunger with the inner edge of the adjacent vane. The outer end 153of each plunger 98 is exposed to the same fluid pressure which acts onthe adjacent vane surface 74.

The inner and outer forces of equal fluid pressure applied to the outerand inner edge surfaces 70, 74 of each vane may be regarded assubstantially ofisetting each other. Yet provision is specifically madefor creating and using pressure imbalances or pressure differentials onthe inner and outer edge surfaces 74, 70 of each vane to materially aidin maintaining optimum engagement of the vane with the cam surface '28as the vane moves through and beyond each fluid discharge zone 154.

In this connection, it is necessary to bear in mind that the maintenanceof optimum engagement of the orbiting vanes with the cam surface 28 notonly involves the matter of continuously applying to each vanesufficient outward force to hold the vane in engagement with the camsurface, but also the avoidance of excessive pressure engagement of eachvane with the cam surface.

As each vane passes through a fluid discharge zone 154 (see FIG. 2) thevane must move inwardly from its fully extended position to itsretracted position. This requires that the vane passing through a fluiddischarge zone be accelerated inwardly by an inward force in contrast tothe outward force which must be applied to each vane to accelerate thevane outwardly as it moves through an intake zone150, as described. Aseach vane 62 moves into a fluid discharge zone 154 the fluid pressure onthe outer edge surface 70 of the vane reaches the full output As eachvane moves into a fluid discharge zone 154,-

the cam surface 28 acts on the vane to' accelerate the vane radiallyinward. When the rotor is turning fast,

vanes moving through afluid discharge zone gain a correspondingly highradially inward velocity.

The radially inward velocity gained by each vane moving through a fluiddischarge zone 154 must be fully dissipated by the time the vane passesfrom the discharge zone into the adjacent sealing zone 156. Otherwise,the vane will move inwardly too far with the result that some or all ofthe vanes will separate from the cam surface 28 and ski jump over an arcof thecam surface upon entering the sealing zone 156 adjacent a fluiddischarge zone 154. The result of any such separation from the camsurface can be a cause of accelerated wear on the cam surface and vanesand a material shortening of the service life of the unit, and it canpermit fluid to pass intermittently from the high pressure fluid zone154 across the sealing zone 156 to the low pressure zone 150 Wheneverthe ski jumping vane is separated from the cam surface 28 within asealing zone 156, thereby materially reducing the efiiciency of theunit.

To avoid jumping or skipping of a portion of the cam surface by vanespassing from a fluid discharge zone 154 to a sealing zone 156 it isnecessary that the inwardly moving vanes be opposed by an outward vanedecelerating force having suflicient strength to overcome the inwardmomentum of each vane and hold it in contact with the cam surface. 7

The outward forc s on each vane passing from a fluid discharge zone 154include the centrifugal force produced by the mass of the vane, theplunger 98 and the springs 134, 136 as well as the forces of the springs134, 136.

Each vane plunger 98, which is rendered hydraulically ineffective tourge the coacting vane outwardly upon entry of the coacting vane into afluid discharge zone 154, again becomes effective to urge the coactingvane outwardly after the vane has passed beyond the discharge zone intointo an adjacent sealing zone 156 and the fluid pressure on the outervane edge surface 70 has dropped below the full output pressure of thepump. However, since the capability of each vane plunger 98 of exertinghydraulically a net outward force on its coacting vane increases as thefluid pressure on the outer vane edge surface 70 decreases, the powerfulhydraulic output force which each vane provides for extending thecoacting vane and maintaining it in optimum pressure contact with thecam .surface as the vane moves through a fluid intake zone and theadjacent transfer zone 152, as described, is not fully available forsupplying radial force needed in maintaining assuredcontact of the vanewith the cam surface as the vane passes from a fluid discharge zone 154into an adjacent sealing zone 156.

The cumulative value of the centrifugal and spring forces acting on eachvane as it passes from a fluid discharge zone 154 may not be sufficientto overcome the inward momentum of the vane and keep it in contact withthe cam surface, particularly at high rotor speeds. In this connection,it should be borne in mind that the strength of the springs 134, 136coacting with each vane is limited by space restrictions withcorresponding limita i tions on the strength of thesprings.

The high pressure plunger 98 associated with each 1 1 of the vanes asthe vanes pass from the fluid discharge zones 154.

Deceleration of the inward velocity of the vanes 62 is very effectivelyaided by a fluid pressure differential dynamically produced and appliedto each vane only as it is needed for decelerating the vane radially.

As shown in FIG. 1, the housing section 33 is shaped to define twoelongated inner fluid outlet ports 159 which open through the rotoropposing surface 36 in radially inward relation to the respective fluidoutlet ports 58, FIG. 2. Each inner discharge port 159 is positionedradially and circumferentially with reference to the axis of the rotorand the corresponding fluid discharge zone 154, so that the innerportion of each vane slot 64 is in communication with theinner port 159when the corresponding vane enters the ramp portion of the cam surface28 'which is within the fluid discharge Zone 154.

As shown, the inner extremities of the individual vane slots 64 areaxially bored with reference to the rotor to have a segmentalcylindrical form 160, FIG. 2, and when each vane 62 is passing throughan early portion of each discharge zone 154 the inner end of thecorresponding vane slot is in communication with the corresponding innerdischarge port 159.

The face 36 of the housing section 38 confronting the rotor 22 is asshown, shaped to define a groove 162 confronting the rotor and extendingfrom each inner fluid outlet port 159 to the leading end of the adjacentouter outlet port 58, FIGS. 2 and13.

While the dynamic fluid action that takes place in each fluid dischargezone 154 can be most simply and accurately visualized with refernce tothe adjacent fluid outlet ports 58 and 159 and outlet grooves 162 in thehousing section 38, it should be pointed out with reference to FIGS. 1and 4 that counterparts of the outlet ports and grooves in the housingsection 38 are formed in the cheek plate 42. For each fluid dischargezone 154, the cheek plate 42 defines an inner port 165, an outer port167, and a groove 163 opening through the plate surface 40 in a patternFIG. 4,.forming substantially a mirror image of the opposing outletports 159, 58 and groove 162 in the housing section 33. One of the innercheek plate ports 165 is connected to the adjacent outer port 167 by thepreviously mentioned passage 124, FIG. 1, and the other inner port 165is connected to the adjacent outer port 167 by a similar passage 16? inthe cheek plate. The outer cheek plate ports 167 communicate throughadjacent portions of the pumping spaces 32 with the opposing outletports 58.

If desired, the grooves 162 and 163 used in the preferred constructionillustrated can be omitted.

Having reference to FIG. 13, each vane 62 upon moving into a fluiddischarge zone 154 is effectively relieved of the outward hydraulicforce of the coacting high pressure plunger 98. This removal of theradially outward hydraulic force on the vane at that point at which itbegins to traverse the cam ramp within the discharge section is highlyadvantageous since it is at this point that the inward acceleration ofthe vane is the greatest and therefore it is at this point that thegreatest frictional forces between the cam surface 23 and the outer endof the vane exist. From the foregoing it will be seen that the tendencyfor the vane to gouge into the cam surface, at least on the leadingportion of the ramp within the discharge section 154 will be minimized.

During an early phase of the movement of a vane through a discharge zone154, FIG. 13, the spring forces and the reversed effective force of vaneacceleration which urge the vane against the cam surface 28 are supplemented by a differential fluid pressure force on the vane produceddynamically as an incident to the forcing of fluid from the coactingvane slot inwardly of the vane. Inward movement of the valve forcesfluid from the inner portion of the coacting vane slot out through theports 159, the vane bores 78 and out through the end 12 grooves 76 inthe vane. The fluid resistance to the outflow of liquid through theports 159, the bores 78 and grooves 76 is relatively low, with theresult that inward resistance to the movement of the vane by hydraulicforces is minimized.

As movement of the vane progresses through a fluid discharge zone 154,the end grooves 76 in the vane move into registry with the outer ends ofthe grooves 162, 163 in the housing section 38 and cheek plate 42,respectively. The grooves 162, 163 are disposed in oblique positionswith reference to the plane of an adjacent vane so that registration oralinement of the grooves 162, 163 with the end grooves 76 in a passingvane begins at the periphery of the rotor 22 and progresses radiallyinward toward the inner edge of the vane as movement of the vanecontinues in the rotary direction described. The effect of this is toprogressively shorten the path of fluid which escapes from the innerportion of each passing vane slot out through the vane end grooves 76 inthe coacting vane into the fluid discharge grooves 162, 163.Consequently, the resistance to the outflow of fluid from beneath thevane is even further reduced by the presence of the grooves 162 and 163,although, as previously stated, these grooves may be omitted if desired,and particularly when the ports 159, are of suflicient size toaccommodate the flow of fluid from beneath the vane in a substantiallyunrestricted manner.

Continued rotary movement of each vane within each fluid discharge zone154 brings the inner portion of the corresponding vane slot 64progressively into full alinement with the inner fluid outlet ports 159,165 for the discharge zone. The effect of this is to reduce andvirtually eliminate the dynamically produced differential pressure onthe vane surfaces 74 and 70 which urges the vane outwardly. The resultis to'minimize the fluid resistance to inward vane movement where suchresistance is undesirable.

After the van passes from the position shown in FIG. 14, the vane mustbe radially decelerated to hold it in engagement with the cam surface28. As illustrated in FIG. 15, continued rotary movement of a vane 62moves the inner portion of the coacting vane slot 64 progressively outof registration with the adjacent inner ports 159, 165 so that the fluidwhich must be subsequently discharged from the inner portion of the vaneslot must pass out through the relatively restricted vane bores 78 andvane end groves 76. The result is to recreate dynamically a pressuredifferential on the inner and outer vane surface '74, 70 which actsoutwardly to aid in de' celerating inward movement of the vane asdesired.

In this connection, it should be appreciated that because of the ratherlarge area of the inner edge surface 74 of each vane, the volume offluid displaced from the coacting vane slot as the vane moves inwardlyis correspondingly large, particularly in relation to the volume offluid displaced by the coacting vane plunger 98 from its cylinder 96.The relatively large volume of the fluid which must pass from each vaneslot 64 Within each fluid discharge zone 154 makes it easier to controlthrotting or choking of the outflow of fluid from each vane slot insynchronized relation to rotary movement of the coacting vane to obtainthe desired radial deceleration of the vane. The rather substantialvolume of fluid involved tends to relax the dimensional tolerances onthe position and size of the grooves 162, 163 and inner ports 159, 165which coact with the vanes to produce the desired dynamic vanedecelerating forces.

As each vane progresses from a fluid discharge zone 154 through theadjacent scaling zone 156, it is effectively urged into sealingengagemednt with the cam surface 28 by the coacting springs 134, 136.Also, there is a progressive escape of high pressure fluid trapped inthe coating vane slot with the result that the pressure on the outeredge surface 79 of the vane progressively decays. The result is aprogressive reactivation of the effectivewhich the vane remains in theintake zone.

ness of the high pressure vane plunger 98 in applying a I net outwardforce to the vane, so that when the vane reaches the next fluid intakezone 150 both the springs 134, 136 and the high pressure plunger arefully effective serve a highly advantageous function in maintaining thecoacting vane in engagement with the cam surface when the high pressurevane plunger 98 is not frilly effective. In particular, the springsserve to great advantage in maintaining contact of the coacting' vanewith the cam surface as the vane moves from each fluid outlet zone 154into and through the adjacent sealing zone 156.

Also, the vane springs 134, 136 serve to advantage when the unit is usedas a fluid motor, in which instance the springs assure contact of thevanes with the cam surface 28 for starting the unit.

As each vane 62 moves outwardly within each fluid intake zone 150, fluidmust flow into the inner portion of the coacting vane slot 54 to fillthe space within the slot inwardly of the vane. The matter ofmaintaining the space with-in each vane slot inwardly of the vane filledwith fluid as the vane moves outwardly within each fluid intake zone 15%is complicated by the relatively low pressure at which the incomingfluid is supplied to the intake zone and the extreme brevity of the timeperiod within In this connection, it should be appreciated that the highspeed with which a vane moves outwardly within each fluid intake zone150 tends to create a suction or partial vacuum at the inner edgesurface 74 of the vane. While this reduction of pressure at the inneredge surface 74 of the vane can aid in sucking fluid into thecorresponding vane slot, the diminution in pressure on the inner vanesurface 74 tends to create a differential pressure on the vane surfaces70 and 74 which acts inwardly to oppose outward movement of the vane.This diflerential pressure can arise dynamically, even though the innerand outer vane edge surfaces 74 and 7 are connected, as described.

Incoming fluid for filling the vane slots 64 inwardly of the vanes 62 issupplied to opposite end faces of the rotor within each fluid intakezone 150 by two inner fluid supply ports 168, 170 formed in the housingsection 38 and check plate 42 to open through the rotor opposingsurfaces 36 and 40 in circumferential alinement with but inwardly spacedrelation to the outer fluid supply ports 52, 54 in each fluid intakezone 150, FIGS. 2, 3 and 4. Even though the inner fluid supply port 168,176 supply fluid to the inner portion of each passing vane groove 64,the movement of fluid into each passing vane groove to minimize dynamiccreation of differential pressure opposing outward vane movement isnevertheless inhibited by the relatively low fluid inlet pressure andthe very limited time available for fluid flow.

In applicants pump, the in flow of fluid into the vane slots is speededup to great advantage by the shape of the space within each slot 64which is filled with fluid upon extension of the coacting vane. Theshaping of this space is such that the inflow of fluid into the space isaccelerated to advantage by centrifugal force acting on the inflowingfluid. This feature of applicants pump is provided to a certain degreein the pump just described, but is provided to a greater degree in themodified pump illustrated in FIGS. 9 and 10 in which component elementscorresponding to component elements of the pump previously described areidentified by the same reference numbers with the addition of the sutfixa.

In the modified pump illustrated in FIGS. 9 and 10, the rotorreinforcing and plunger cylinder defining structure which extendsradially outward beyond the inner extremities of the respective vaneslots 64a is formed as an 14 formed in the inner portion of each vane62a is shaped to diverge in a radially inward direction, as illustratedin FIG. 9, so that the opposite side edges intersect opposite axial endsof the vanes at the inner extremities of the vanes. The bottom of eachvane slot 64a is shaped tohave, as viewed in a transverse axial sectionof,the rotor, FIG. 9, a truncated triangular form projecting out intothe coacting vane notch and corresponding generally in shape to thenotch, as shown. Thus, the-space 182 between the bottom of each vaneslot and the inner edge of the adjacent vane slopes radially outwardfrom the two ends of the rotor.

Consequently, when the inner ends of the vane, slots 64a move intoalinement with a pair of inner fluid supply ports, the incipient flow offluid from the inner ports into the vane slot space 182 is immediatelysubjected to centrifugal force which accelerates the flow of fluidtoward the center of the vane space 182 which is located radiallyoutward of the opposite ends of the space 182. Hence, this shaping ofthe vanes and slots so that the central portion of each slot space 182is located radially outward of the axial end portions of the space 182produces a highly advantageous centrifugal pumping action that greatlyaccelerates the inflow of fluid into each slot, as desired.

It will be appreciated, with reference to FIG. 9, that the inte ralportion of the rotor 22a which extends out into each vane notch 82a asillustrated and described constitutes an integral protuberance 184 ofthe rotor which provides the desired mutual reinforcement of adjacentsectors 151a of the rotor which define the adjacent rotor slot. Each.integral rotor protuberance 184 is bored to define a cylinder 96a forthe corresponding high pressure vane plunger 98a.

-The enlarged plugs 8412 provide for a stronger mutual reinforcement ofthe rotor sectors 151]) intervening between and defining the vane slots64b.

It will be appreciated that even though the notch 82b in each vane 62bdoes not progressively widen in a radially inward direction, the centralportion of the notch is V located radially outward of the innerextremities of the vane, which are disposed at opposite axial ends of,the vane. As a consequence, incoming fluid flowing into the vane notch82b is subjected to centrifugal forcewhich aids materially in fillingthe coacting vaneslot 64b inwardly of the vane moves outwardly, asdescribed. .In

a similar manner, the inflow of fluid into the notch 82 in each vane 62in the pump first described is accelerated by centrifugal force.

It will be appreciated that the invention is not necessarily limited touse of the particular constructions illustrated, but includes use ofvariants and alternatives within the spirit and scope of the inventionas defined by the claims.

The invention is claimed as follows:

1. A rotary vane fluid power'unit comprising, in combination, a rotor, ahousing encasing said rotor and including means defining a cam surfaceencircling said rotor, said cam surface being shaped and positioned inrelation to the periphery of said rotor to define therewith .a workingspace for fluid, said housing defining flow passages communicating withsaid space at spaced positions therealong, said rotor defining anannular series of vane slots therein opening outwardly through theperiphery of the rotor and being separated by intervening sectors of therotor, a plurality of vanesmounted in said respective slots to extendfrom the periphery of the rotor into continuous engagement with said camsurface, each vane being slidable in its slot betwen a fully extendedposition and a fully retracted position to effect continuous engagementof the outer marginal edge of the vane with said cam surface uponrotation of the rotor, each vane having an inner edge disposed withinthe corresponding vane slot for all positions of the vane and beingshaped to define in an inner portion of the vane a notch extendingbetween opposite sides of the vane and extending outwardly in the vanefor an extended distance from the inner extremity of the vane, plugsdisposed within said respective vane slots to extend into said notchesof the coacting vanes for substantial distances outwardly of thepositions occupied by the inner extremities of the respective vanes whenthe respective vanes are moved into their retracted positions in theslots by said cam surface, said plugs each being shaped and dimensionedto firmly engage simultaneously the two opposing side surfaces of theassociated slot to effect by means of the plugs a mutual reinforcementof said intervening rotor sectors, the portion of each intervening rotorsector located radially inward of the radial positions of the inneredges of the fully extended adjacent vanes being of solid constructionthat is impervious to the passage of fluid therethrough between theadjacent slots and having a minimum axial width that is at leastsubstantially equal to the maximum axial width of the portion of eachadjacent vane that extends outwardly from the periphery of the rotorwhen the vane is fully extended, each of said plugs defining a cylindertherein generally parallel to the plane of the adjacent vane and openingoutwardly toward the inner edge of the adjacent vane at the bottom ofsaid notch in the vane, a plunger slidably mounted in said cylinder ofeach p ug to react outwardly on the adjacent vane, means for supplyingfluid under pressure from the high pressure end of said working space tosaid plug cylinders at the inner ends of said piungers to apply fluidpressure to Said plungers for urging said vanes outwardly, each of saidvanes defining two surfaces thereupon which are substantiallycontinuously exposed to the pressure of fluid in the interspace adjacentthe vane between the periphery of the rotor and said cam surface, one ofsaid surfaces on each vane being oriented so that the force of fluidpressure on the vane urges the vane away from said cam surface and theother of said surfaces on each vane being oriented so that the force offluid pressure thereon urges the vane toward said cam surface, springmeans disposed within each of said vane slots and being stressedcontinuously to urge the adjacent vane outwardly in the vane slot, saidspring means in each slot having a movable power applying portion whichacts on the adjacent vane and moves in and out with the vane as the vanemoves in and out in its slot, and'said spring means in each slot havinga support portion which reacts on the rotor to transmit thereto thereaction of the adjacent vane on the spring means and which isstationary with respect to the rotor so that the spring means is flexedand stores energy upon inward movement of the vane and subsequentlyreleases energy by relaxation to extend the vane.

2. A rotary vane fluid power unit comprising, in combination, a rotor, ahousing encasing said rotor and including means defining a cam surfaceencircling said rotor, said cam surface being shaped and positioned inrelation to the periphery of said rotor to define therebetween a workingspace for fluid, said housing defining flow passages communicating withsaid working space at spaced positions therealong, an annular series ofcircumferentially spaced vane units carried by said rotor, each vaneunit including a vane mounted in a coacting slot defined by said rotor,each vane being slidable within its coacting slot to project therefrominto sliding engagement with said cam surface, each vane unit definingfirst and second vane biasing surfaces associated with the coacting vaneoutwardly, each vane unit includingmeans associated therewith to isolatesaid third biasing surface thereof from direct communication with saidsecond biasing surface of the unit, means associated with each unit forsupplying to said third biasing surface thereof fluid under highpressure from a high pressure portion of said working space for fluid,each vane unit including spring means stressed to urge the vane of thevane unit outwardly in its coacting vane slot, said spring means of eachvane unit having a movable power applying portion which acts on the vaneof the vane unit and moves in and out with the vane as the vane moves inand out in its slot, and said spring means of each vane unit having asupport portion which reacts on the rotor to transmit thereto thereaction of the coacting vane on the spring means and which issubstantially stationary with respect to the rotor so that the springmeans is flexed and stores energy upon inward. movement of the vane andsubsequently releases energy by relaxation to extend the vane.

3. A rotary vane fluid power unit comprising, in combination, a rotor, ahousing encasing said rotor and including means defining a cam surf-aceencircling said rotor, said cam surface being shaped and positioned inrelation to the periphery of said rotor to define therewith a space forfluid, said housing defining flow passages communicating with said spaceat spaced positions thereaiong, said rotor defining therein an annularseries of outwardiy open vane slots separated by intervening sectors ofthe rotor, a plurality of vanes slidably in said respective slots toextend from the periphery of the rotor into continuous engagement withsaid cam surface, each vane being slidable in its slot between aretracted position and an extended position to effect continuousengagement of the outer mar inal edge of the vane with said cam surfaceupon rotation of the rotor, each vane having an inner edge disposedwithin the corresponding vane slot for all positions of the vane andbeing shaped to define in an inner portion of the vane a notch extendingbetween opposite sides of the vane and extending outwardly in the vanefor an extensive distance from the inner extremity of the vane, a rotorreinforcing plug disposed within each of said vane slots and extendinginto said notch of the coacting vane for a substantial distanceoutwardly of the position occupied by the inner extremity of the vanewhen the vane is moved into its retracted position in its slot by saidcam surface, each of said plugs being shaped and dimensioned to firmlyengage simultaneously the two opposing side surfaces of the associatedslot to effect by means of the plugs a mutual reinforcement of saidintervening rotor sectors, the portion of each intervening rotor sectorlocated radially inward of the radial positions Of the inner edges ofthe fully extended adjacent vanes being of solid construction that isimpervious to the passage of fluid therethrough between the adjacentslots and having a minimum axial width that is at least substantiallyequal to the maximum axial width of the portion of each adjacent vanethat extends outwardly from the periphery of the rotor when the vane isfully extended, each of said plugs defining a cylinder therein openingoutwardly toward the inner edge of the vane at the bottom of said notchin the vane, a plunger slidably mounted in said cylinder of each plug toreact outwardly on the adjacent vane, means for supplying fluid underpressure from said fluid space to said plug cylinders at ing meansproviding communication between the inner' edgeof the vane and the interspace adjacent the vane between the periphery of the rotor and said camsurface so that the force of fluid pressure on the outer end of eachvane tending to urge the vane inwardly is opposed by the force of fluidpressure on the inner edge of the vane tending to urge the vaneoutwardly.

4. A rotary vane fluid power unit comprising, in combination, a rotor, ahousing encasing said rotor and including means defining a cam surfaceencircling said rotor and coacting therewith to define a fluid workingspace having fluid inlet and outlet zones, said housing definingpassageways communicating with said inlet and outlet zones of saidworking space, said rotor defining therein an annular series of vaneslots opening outwardly through the periphery of the rotor and beingseparated by intervening sectors of the rotor, a plurality of vanesmounted in said respective vane slots to extend from the periphery ofthe rotor into continuous engagement with said cam surface, each vanebeing slidable in its slot between a retracted position and an extendedposition to effect continuous engagement of the outer marginal edge ofthe vane with said cam surface upon rotation of the rotor, eachvanebeing shaped to have an inner end portion which extends outwardly asubstantial distance from the inner extremity of the vane and has atransverse sectional area which is materially less than thecorresponding transverse sectional area of a portion of the vane locatedoutwardly of said inner end portion, each of said vane slots includingan inner'portion adapted to receive said inner portion of the coactingvane and being reduced in transverse sectional area in relation to thetransverse sectional area of an outer portion of the vane slot by anelement which is rigid with the rotor and positioned to overlap saidinner end portion of the coacting Vane when the latter is in a retractedposition, the portion of each intervening rotor sectorthat extendsradially inward from the radial positions of the inner edges of thefully extended adjacent vanes being of solid construction that isimpervious to the passage of fluid therethrough between the adjacentslots and having a minimum axial width that is at least substantiallyequal to the maximum axial width of the portion of each adjacent Vanethat extends outwardly from the periphery of the rotor when the vane isfully extended, said element in each vane slot defining a cylinderopening outwardly toward the opposing inner edge of the coacting vane, aplunger slidably mounted in each cylinder to act outwardly on theadjacent vane, means including an automatic pressure switching valveconnecting inlet and outlet zones of said working space with aidcylinders to supply fluid automatically from the zone under the higherfluid pressure to each cylinder to act on the plunger therein to urgethe plunger and the coacting vane outwardly, each of said vanes and thestructure associated therewith including means for supplying fluid tothe inner edge of the vanes to oppose the inward force of fluid pressureon the outer edge of the vane, spring means disposed Within each of saidvane slots and being stressed to urge the adjacent vane outwardly in thevane slot, said spring means in each slot having a movable powerapplying portion which acts on the adjacent vane and moves in and outwith the vane as the vane moves in and out in its slot, and said springmeans in each slot having a support portion which reacts on the rotor totransmit thereto the reaction of the adjacent vane on the spring meansand which is stationary with respect to the rotor so that the springmeans is flexed and stores energy upon inward movement of the vane andsubsequently releases energy by relaxation to extend the vane.

5. A rotary vane fluid power unit comprising, in combination, a rotor, ahousing encasing said rotor and including means defining a cam surfaceencircling said rotor,

18 said cam surface being shaped and positioned in relation to theperiphery of said rotor to define therewith a space for fluid, saidhousing defining flow passages communieating with said space at spacedpositions therealong, said rotor defining an annular series of vaneslots opening outwardly through the periphery of the rotor and beingseparated by intervening sectors of the rotor, a plurality of vanesmounted in said respective slots to extend from the periphery of therotor into engagement withsaid cam surface, each vane being slidable inits slot between'a retracted position and an extended position-to eifectcontinuous engagement of the outer marginal edge of the vane with saidcam surface upon rotation of the rotor, each vane having an inner edgedisposed within the corresponding vane slot for all positions of thevane and being shaped to define in an inner portion of the vane a notchextending between opposite sides of the vane and extending outwardly inthe vane from the inner extremity of the the rigid elements effect amutual reinforcement of said intervening rotor sectors, the portion ofeach intervening rotor sector located radially inward of the radialpositions of the inner edges of the fully extended adjacent vanes beingof solid construction that is impervious to the passage of fluidtherethrough between the adjacent slots and having a minimum axial widththat is at least substantially equal to the maximum axial Width of theportion of each adjacent vane that extends outwardly from the peripheryof the rotor when the vane is fully extended, each of said rigidelements defining a cylinder therein generally parallel to the plane ofthe adjacent vane and opening outwardly toward the inner edge of theadjacent vane, a plunger slidably mounted in said cylinder of each rigidelement and coacting with the adjacent vane to react outwardly thereon,meansfor supplying fluid under pressure from said fluid space to saidcylinders at the inner ends of said plungers to apply fluid pressure tosaid plungers for urging said vanes outwardly, each of said vanes andthe structure coacting therewith including means for applying fluidpressure to the inner edge of the vane to urge the vane outwardly,spring means coacting with each of said vanes and being stressed to urgethe vane outwardly in its slot, said spring means for each vane having amovable power applying portion which acts on the vane and moves in andout with the vane as the vane moves in and out in its slot, and saidspring means for each vane having a support portion-Which reacts on therotor to transmit thereto the reaction of the coacting vane on thespring means and which is stationary with respect to the rotor so thatthe spring means is flexed and stores energy upon inward movement of thevane and subsequently releases energy by relaxation to extend the vane.

6. A rotary vane fluid power unit comprising, in combination, a rotor, ahousing encasing said rotor and including means defining a cam surfaceencircling said rotor and defining with the periphery thereof a Workingspace for fluid, said rotor defining therein an annular series of vaneslots opening outwardly through the periphery of the rotor and beingseparated by intervening sectors of the rotor, a plurality of vanesmounted in said respective vane slots to extend from the periphery ofthe rotor into continuous engagement with said cam surface, each vanebeing slida'ble in its slot between a retracted position and an extendedposition to effect continuous engagement of the outer marginal edge ofthe vane with said cam surface upon rotation of the rotor, each vanehaving an inner edge disposed within the corresponding vane slot forallpositions of the vane, each vane being shaped to havean inner endportion which extends outwardly a substantial distance from the innerextremity of the vane and has a transverse sectional area which ismaterially less than the corresponding transverse sectional area of aportion of the vane located outwardly of said inner end portion, each ofsaid vane slots including an inner portion adapted to receive said innerportion of the coacting vane and being reduced in transverse sectionalarea in relation to the transverse sectional area of an outer portion ofthe vane slot by an element which is rigid with the rotor and positionedto overlap said inner end segment of the coacting vane when the latteris in a retracted position, the portion of each intervening rotor sectorlocated radially inward of the radial positions of the inner edges ofthe fully extended adjacent vanes being of solid construction that isimpervious to the passage of fluid therethrough between the adjacentslots and having a minimum axial width that is at least substantiallyequal to the maximum axial width of the portion of each adjacent vanethat extends outwardly from the periphery of the rotor when the vane isfully extended, said element in each vane slot defining a cylinderopening outwardly toward the opposing inner edge of the coacting vane, aplunger slidably mounted in each cylinder to act outwardly on theadjacent vane, said rotor having means thereon providing communicationbetween :1 high pressure Zone of said working space and said cylindersto supply high pressure fluid to each cylinder to act on the inner endof the plunger therein to urge the plunger and the coacting vaneoutwardly, and each of said vanes and the structure associated therewithincluding means providing communication between the inner edge of thevane and the interspace adjacent the vane between the rotor and theouter end of the vane.

7. A rotary vane fluid power unit comprising, in combination, a rotor; ahousing encasing said rotor and including means defining a cam surfaceencircling said rotor and coacting therewith to define, for fluid,working space having fluid inlet and outlet zones; said housingincluding means defining passageways communicating with said inlet andoutlet zones of said working space, said rotor defining an annularseries of vane slots therein opening outwardly through the periphery ofthe rotor and being separated by intervening sectors of the rotor, aplurality of vanes mounted in said respective vane slots to extend fromperiphery of the rotor into engagement with said cam surface, each vanebeing slidable in its slot between a retracted position and an extendedposition to effect continuous engagement of the outer marginal edge ofthe vane with said cam surface upon rotation of the rotor, each vanehaving an inner edge disposed within the corresponding vane slot for allpositions of the vane and being shaped to define in an inner portion ofthe vane a notch extending outwardly in the vane from the innerextremity thereof, a plurality of plugs fitted into said respective vaneslots to extend outwardly into said notches in the respective vanes,said plugs each engaging firmly the two rotor sectors on opposite sidesof the corresponding slot to effect mutual reinforcement of saidintervening rotor sectors, the portion of each intervening rotor sectorlocated radially inward of the radial positions of the inner edges ofthe fully extended adjacent vanes being of solid construction that isimpervious to the passage of fluid therethrough between the adjacentslots and having a minimum axial width that is at least substantiallyequal to the maximum axial width of the portion of each adjacent vanethat extends outwardly from the periphery of the rotor when the vane isfully extended, spring means disposed within each of said vane slots andbeing stressed to urge the adjacent vane outwardly in the vane slot,said spring means in each slot having a movable power applying portionwhich acts on the adjacent vane and moves in and out with the vane asthe vane moves in an out in its slot, said spring means in each slothaving a support portion which reacts on the rotor to transmit theretothe reaction of the 2Q adjacent vane on the spring means and which isstationary with respect to the rotor so that the spring means is flexedand stores energy upon inward movement of the vane and subsequentlyreleases energy by relaxation to extend the vane, each of said plugsdefining a cylinder therein, a plunger disposed in each of said plugcylinders and coacting with the adjacent vane to apply an outward forcethereto, means including an automatic pressure switching valveconnecting inlet and outlet zones of said working space with saidcylinders to supply fluid automatically from the zone under the higherfluid pressure to each cylinder to act on the plunger therein to urgethe plunger and the coacting vane outwardly, and each of said vanes andthe structure associated therewith including means for supplying fluidto the inner edge of the vane to oppose the inward force of fluidpressure on the outer edge of the vane.

8. A rotary vane fluid power unit comprising, in combination, a rotor, ahousing encasing said rotor and including means defining a cam surfaceencircling said rotor and being shaped and positioned in relation to theperiphery of the rotor to define therebetween a working space for fluid,said rotor defining therein an annular series of vane slots openingoutwardly through the periphery of the rotor and being separated byintervening sectors of the rotor, a plurality of vanes mounted in saidrespective vane slots to extend from the periphery of the rotor intocontinuous engagement with said cam surface, each vane being shaped tohave an inner end segment which has a transverse sectional area which ismaterially less than the corresponding transverse sectional area of aportion of the vane located outwardly of the inner end segment thereof,each of said vane slots including an inner segment adapted to receivesaid inner segment of the coacting vane and being reduced in transversesectional area in relation to the transverse sectional area of an outerportion of the vane slot by an element which is rigid with the rotor andpositioned to overlap said inner end segment of the coacting vane whenthe latter is in a retracted position, the portion of each interveningrotor sector located radially inward of the radial positions of theinner edges of the fully extended adjacent vanes being of solidconstruction that is impervious to the passage of fluid therethroughbetween the adjacent slots and having a minimum axial width that is atleast substantially equal to the maximum axial width of the portion ofeach adjacent vane that extends outwardly from the periphery of therotor when the vane is fully extended, said element in each vane slotdefining a cylinder opening outwardly toward the opposing inner edge ofthe coacting vane, a plunger slidably mounted in each cylinder to actoutwardly on the adjacent vane, said rotor having means thereonproviding communication between a high pressure zone of said workingspace and said cylinders to supply high pressure to act on the inner endof the plunger therein to urge the plunger and the coacting vaneoutwardly, each of said vanes and the structure associated therewithincluding means providing communication between the inner edge of thevane and the interspace adjacent the vane between the rotor and theouter end of the vane, spring means coacting with each vane and beingstressed continuously to apply to the vane an outward force which iscumulative with the outward forces on the vane of fluid pressure actingon the inner edge of the vane and fluid pressure acting on the coactingplunger said spring means for each vane having a movable power applyingportion which acts on the Vance and moves in and out with the vane asthe vane moves in and out in its slot,

and said spring means for each vane having a support portion whichreacts on the rotor to transmit thereto the reaction of the vane on thespring means and which is stationary with respect to the rotor so thatthe spring means is flexed and stores energy upon inward movement of thevane and subsequently releases energy by relaxation to extend the vane.

9. A rotary vane fluid power unit comprising, in combination, a rotor, ahousing encasing said rotor and including means defining a cam surfaceencircling said rotor, said cam surface being shaped and positioned inrelation to the periphery of said rotor -to define therewith a workingspace for fluid, said housing defining flow passages communicating withsaid space at spaced positions th-erealong, said rotor defining anannular series of vane slots therein opening outwardly through theperiphery of the rotor and being separated by intervening sectors of therotor, a plurality of vanes mounted in said respective slots to extendfrom the periphery of the rotor into continuous engagement with said camsurface, each vane being slidable in its slot between a retractedposition and a fully extended position to effect continuous engagementof the outer marginal edge of the vane with said cam surface uponrotation of the rotor, each vane having an inner edge disposed withinthe corresponding vane slot for all positions of the vane and beingshaped to define in an inner portion of the vane a notch extendingbetween opposite sides of the vane and extending outwardly in the vanefor an extended distance from the inner extremity of the vane, and plugsdisposed within said respective vane slots to extend into said notchesof the coacting vanes for substantial distances outwardly of the innerextremities of the respective vanes when the respective vanes are movedinto retracted positions in the coacting slots by said cam surface, saidplugs each being shaped and dimensioned to firmly engage simul taneouslythe two opposing side surfaces of the associated slot to effect by meansof the plugs a mutual reinforcement of said intervening rotor sectors,the portion of each intervening rotor sector located radially inward ofthe radial positions of the inner edges of the fully extended adjacentvanes being of solid construction that is impervious to the passage offluid therethrough between the adjacent slots and having a minimum axialwidth that is at least substantially equal to the maximum axial width ofthe portion of each adjacent vane that extends outwardly from theperiphery of the rotor when the vane is fully extended.

' It). A rotary vane fluid power unit comprising, in combination, arotor, a housing encasing said rotor and including means defining a camsurface encircling said rotor and coacting therewith to define a fluidworking space having fluid inlet and outlet-zones, said rotor definingan annular series of vane slots opening outwardly through the peripheryof the rotor and being separated by intervening sectors of the rotor, aplurality of vanes mounted in said respective vane slots to extendoutwardly therefrom into engagement with said cam surface, each vanebeing shaped to have a radially inner portion which extends outwardly asubstantial distance from the inner extremity of the vane and has anarea in transverse section generally parallel to the axis of the rotorthat is materially less than the corresponding transverse sectional areaof a portion of the vane located outwardly of said inner portion, eachof said vane slots including an inner portion adapted to receive saidinner portion of the coacting vane and having an area in a transversesection generally parallel to the rotor axis which is reduced inrelation to the corresponding transverse sectional area of an outerportion of the vane slot by an element which is rigid with the rotor andpositioned to overlap said inner portion of the coacting vane when theperiphery of the rotor when the vane isfully extended, said elementcorresponding to each vane slot defining a cylinder opening outwardlytoward the opposing inner edge of the coacting vane, a plunger slidablymounted in each cylinder to act outwardly on the adjacent vane, meansincluding an automatic pressure switching valve connecting said inletand said outlet zones of said working space with said cylinders tosupply fluid automatically from the zone under the higher fluid pressureto each cylinder to "act on the plunger therein to urge the plunger andthe coacting vane outwardly, and each vane having associated therewithmeans providing continuous communication for fluid between the inner andouter edges of the vane.

11. A rotary vane pump comprising in combination, a rotor, housing meansencasing said rotor and including means defining a cam surfaceencircling said rotor and defining therewith a fluid working spacehaving an inlet zone and an outlet zone, said housing means includingfluid supply means for supplying fluid to said working space at saidinlet zone thereof, said housing means in cluding means for dischargingfluid from said outlet zone of the working space, said rotor defining anannular series of vane slots, a plurality of vanes slidably mounted insaid respective vane slots to extend outwardly therefrom int-oengagement with said cam surface for movement along said cam surfacethrough said working space upon rotation of the rotor, said fluid supplymeans including means defining fluid supply passages confrontingopposite ends of said rotor and registering radially with adjacent innerportions of passing vane slots to supply fluid to the inner portion ofeach-of said vane slots at both ends of the rotor as an incident tomovement of the associated vane through said intake zone of said workingspace, each vane having an inner edge shaped to have radially inwardextremities located adjacent opposite ends of said rotor and to have anoutwardly offset medial portion located radially outward of said innerextremities of the vane, and the inner portion of each vane slot beingshaped and dimensioned in relation to the inner edge of the adjacentvane to provide upon outward displacement of the vane from its innermostposition free flowing so that fluid entering the inner portion of eachvane slot from said passages is centrifugally urged toward said medialand defining therewith a fluid working space having an inlet zone and anoutlet zone, said rotor defining an annular series of vane slots, aplurality of vanes slidably mounted in said respective vane slots toextend, outwardly therefrom into engagement with said cam surface formovement along said cam surface through said working space upon rotationof the rotor, said housing means including fluid supply meanscommunicating with said fluid working space at said inlet zone thereofand defining fluid supply passage space confronting opposite ends ofsaid rotor at positions that are alined circumferentially with inletzone and that register radially with the inner portions of the vaneslots opening through the two ends of the rotor to supply fluid to theinner portion of each of said vane slots at both ends of the rotor as anincident to movement of the associated vane through said intake zone ofsaid working space, and each vane having two inner extremeties locatedadjacent opposite 1 ends of the rotor and having an inner edge that isshaped between said inner extremities of the vane to define a medialnotch having opposite sides diverging radially in-' Ward so that fluidentering the inner portion of the coacting slot from said passage spaceat opposite ends of the rotor is centrifugally urged to flow radiallyoutward and axially inward along the inwardly diverging sides of said-vane notch toward the center of said vane notchto fill 23 the slotinwardly of the vane as the vane moves outwardly in said inlet zone.

13. A rotary vane fluid pump comprising, in combination, a rotor, meansdefining a cam surface encircling said rotor and defining therewith apumping space having fluid inlet and outlet zones, fluid supply meansfor supplying fluid to said pumping space at said inlet zone thereof,said rotor defining an annular series of vane slots opening outwardlythrough the periphery of the rotor, a plurality of vanes slidablydisposed in said respective slots for engagement with said cam surface,each of said vanes having an inner portion thereof defining a notchopening radially inward and having side edges diverging in a radiallyinward direction to inner extremities of the vane located adjacentopposite ends of the rotor, rneans on said rotor defining a plurality ofprotuberances corresponding to said respective slots, each protuberancebeing positioned with reference to its corresponding slot to extendoutwardly into said notch in the coacting vane when the vane is in aretracted position, and said fluid supply means including means definingfluid supply passage spaces confronting opposite ends of said rotor inpositions which register with the radially inward portions of the vaneslots in the rotor as the slots move the coacting vanes through saidinlet zone of said pumping space.

14. A rotary vane fluid pump comprising, in combination, a rotor, meansdefining a cam surface encircling said rotor and defining therewith apumping space ha ing fluid inlet and outlet zones, fluid supply meansfor supplying fluid to said pumping space at said inlet zone thereof,said rotor defining an annular series of vane slots opening outwardlythrough the periphery of the rotor, a plurality of vanes slidablydisposed in said respective slots for engagement with said cam surface,each of said vanes having an inner portion thereof defining a notchopening radially inward and having side edges diverging in a radiallyinward direction to inner extremities of the vane located adjacentopposite ends of the rotor, a plurality of rotor reinforcing elementscorresponding to said respective slots, each reinforcing element beingpositioned with reference to the coacting slot to extend into said notchin the coacting vane when the vane is in a retracted position, eachreinforcing element extending between and firmly coacting with portionsof the rotor on opposite sides of the correspond ing slot to effectmutual reinforcement of portions of the rotor defining the slot, eachreinforcing element defining a plunger cylinder therein, a plungerslidably disposed in each cylinder and engaging the coacting vane, meansfor supplying fluid under pressure to each cylinder to urge the coactingplunger and vane outwardly, said fluid supply means including meansdefining fluid supply passage spaces confronting opposite ends of saidrotor in positions which register with the radially inward portions ofthe vane slots in the rotor as the slots move the coacting vanes throughsaid inlet zone of said pumping space, and spring means coacting witheach vane to urge the vane outwardly.

15'. A rotary vane fluid power unit comprising, in combination, a rotor,housing means encasing said rotor and including means defining a camsurface encircling said rotor and defining therewith a fluid workingspace having fluid inlet and outlet zones, said rotor defining anannular series of vane slots opening outwardly through the periphery ofthe rotor, a plurality of vanes slidably disposed within said respectivevane slots for engagement with said cam surface, said housing meansincluding means for supplying fluid to the intake zone of said fluidworking space, said housing means including fluid outlet means forreleasing fluid from said outlet zone of said fluid working space, saidfluid outlet means includ ing means defining outlet passage spaceconfronting one end of said rotor, and said outlet passage space havinga position such that upon turning of said rotor to discharge fluid fromsaid outlet zone of said working space each vane slot carrying a vanethrough the outlet zone of the working space is brought into analinement with the passage space which alinement reaches a maximum valuewhen the coacting vane is passing through a medial portion of said fluidoutlet zone and which is greatly reduced before the coacting vane passesbeyond said fluid outlet zone.

16. A rotary vane fluid power unit comprising, in combination, a rotor,housing means encasing said rotor and including means defining a camsurface encircling said rotor and defining therewith a fluid workingspace having fluid inlet and outlet zones, said rotor defining anannular series of vane slots opening outwardly through the periphery ofthe rotor, a plurality of vanes slidably disposed within said respectivevane slots for engagement with said cam surface, said housing meansincluding means for supplying fluid to the intake zone of said pumpingspace, said housing means including fluid outlet means for releasingfluid from said outlet zone of said fluid working space, said fluidoutlet means including means defining an inner fluid outlet portconfronting one end of said rotor inwardly of the periphery of the rotorand being positioned for registration with the radially inward portionof each vane slot as the vane slot carries the coacting vane through amedial portion of said outlet zone of said fluid working space, each ofsaid vanes defining in the axial end thereof adjacent said one end ofsaid rotor a groove extending from the inner to the outer edge of thevane; said housing means including means defining a fluid outlet passageconfronting said one end of the rotor and extending generally from saidinner outlet port to the periphery of the rotor and having a positionalorientation such that, upon turning of said rotor in a rotary directionwhich discharges fluid from said working space outlet zone, said endgroove in each vane passing through said outlet zone of said fluidworking space establishes a communicating alinement with said outletpassage which begins at the periphery of the rotor and progressesinwardly to progressively reduce the resistance to the outflow of fluidthrough the vane end groove from the coacting vane slot; and said innerport being positioned so that the degree of the registration of theinner port with each vane slot carrying a vane in said rotary directionthrough the outlet zone of the fluid working space reaches a maximumdegree when the coacting vane is passing through a medial portion ofsaid fluid outlet zone and is greatly reduced before the coacting vanepasses beyond said fluid outlet zone.

17. A rotary vane fluid power unit comprising, in combination, a rotor,housing means encasing said rotor and including means defining a camsurface encircling said rotor and defining therewith a fluid workingspace having fluid inlet and outlet zones, said rotor defining anannular series of vane slots opening outwardly through the periphery ofthe rotor, a plurality of vanes slidably disposed within said respectivevane slots for engagement with said cam surface, said housing'meansincluding means for supplying fluid to the intake zone of said pumpingspace, said housing means including fluid outlet means for releasingfluid from said outlet zone of said fluid Working space, said fluidoutlet means including means defining outlet passage space confrontingone end of said rotor, each of said vanes defining in the axial endthereof adjacent said one end of said rotor a groove extending from theinner to the outer edge of the vane; said outlet passage space beingshaped and being positioned relative to said working space outlet zoneso that, upon turning of said rotor in a rotary direction whichdischarges fluid from said outlet zone, said end groove in each vanepassing through said outlet zone establishes a communicating alinementwith said outlet passage space which begins adjacent the periphery ofthe rotor and progresses inwardly to progressively reduce the resistanceto the outflow of fluid through the vane end groove from the coactingvane slot; and the position of said outlet passage space relative tosaid outlet zone being such that the inner portion of each slot carryinga vane in said rotary direction through said outlet zone moves intoalinement with said passage space but passes out of alinement with saidpassage space before the coacting vane passes beyond said fluid outletzone.

18. A rotary vane fluid power unit comprising, in combination, a rotor,housing means encasing said rotor and including means defining a camsurface encircling said rotor and defining therewith a fluid workingspace having fluid inlet and outlet zones, said rotor defining anannular series of vane slots opening outwardly through the periphery ofthe rotor, a plurality of vanes slidably disposed within said respectivevane 'slots for engagement with said cam surface, a plurality of rotorreinforcing elements corresponding to said respective vane slots, eachrotor reinforcing element extending between opposite sides of thecorresponding vane slot and firmly coacting with portions of the rotoron opposite sides of the slot to effect mutual reinforcement of therotor portions defining the slot at a position disposed outwardly of theinner extremity of the slot, each vane having a radially inner portionshaped to overlap the adjacent rotor reinforcing element for an extendeddistance when the vane is in its retracted position, said housing meansincluding means for supplying fluid to the intake zone of said pumpingspace, said housing means including fluid outlet means for releasingfluid from said outlet zone of said fluid working space, said fluidoutlet means including means defining outlet passage space confrontingone end of said rotor, each of said vanes defining in the axial endthereof adjacent said one end of said rotor a groove extending from theinner edge to the outer edge of the vane; said outlet passage spacebeing shaped and being positioned relative to said Working space outletzone so that, upon turning of said rotor in a rotary direction whichdischarges fluid from said outlet zone, said end groove in each vanepassing through said outlet zone establishes a communicating alinementwith said outlet passage space which begins adjacent the periphery ofthe rotor and progresses inwardly to progressively reduce the resistanceto the outflow of fluid through the vane end groove from the coactingvane slot; and the position of said outlet passage space relative tosaid outlet zone being such that the inner portion of each slot carryinga vane in said rotary direction through said outlet zone moves intoalinement with said passage space but passes out of alinement with saidpassage space before the coacting vane passes beyond said fluid outletzone.

19. A rotary vane fluid power unit comprising, in combination, a rotor,a housing encasing said rotor and including means defining a cam surfaceencircling said rotor and defining therewith a fluid working space, saidrotor defining an annular series of vane slots, a plurality of vanesslidably mounted in said respective slots to extend outwardly therefrominto engagement with said cam surface, a plurality of rotor reinforcingelements correspond- 1 ing to said respective vane slots and beingdisposed within the limits of said slots along the axis of the rotor,each rotor reinforcing element extending outwardly a substantialdistance beyond the inner extremity of the corresponding vane slot andextending between opposite sides of the slot in firmly coacting relationto portions of the rotor on opposite sides of the slot to effect mutualreinforcement of the rotor portions defining the slots, each vane havinga radially inner portion shaped to overlap the adjacent rotorreinforcing element for an extended distance when the vane is in itsretracted position, each vane having a radially outer portion whichextends between and Which is substantially flush with opposite ends ofthe adjacent portion of the rotor, each of said rotor reinforcingelement defining a cylinder opening outwardly toward the opposing inneredge of the coacting vane, a

plunger slidably mounted in each-cylinder to actoutwardly on theadjacent vane, means for supplying fluid under pressure to each cylinderto act on the plunger therein to urge the plunger and the coacting vaneoutwardly, and each vane having associated therewith means providingcommunication for fluid between the inner and outer edges of the vane.

20. A rotary vane fluid pump comprising, in combination, a rotor, meansdefining a cam surfaceencircling said rotor and defining therewith apumping space having fluid inlet and outlet zones, fluid supply meansfor supplying fluid to said pumping space at said inlet zone thereof,said rotor defining an annular series of vane slots opening outwardlythrough the periphery of the rotor, a plurality of vanes slidablydisposed in said respective slots for engagement with said cam surface,each of said vanes having an inner portion thereof defining a notchopening radially inward and having side edges diverging in a radiallyinward direction to inner extremities of the vane located adjacentopposite ends of the rotor, means on said rotor defining a plurality ofprotuberances corresponding to said respective slots, each protuberancebeing positioned with reference to its corresponding slot to extendoutwardly into said notch in the coacting vane when the vane is in aretracted position; each protuberance having an outer edge confrontingthe inner edge of the corresponding vane and having a shape, as viewedin a section thereof taken axially with respect to the rotor, whichconforms generally to the shape of the notch in the vane; each ofsaidprotuberances defining a cylinder therein, a plunger mounted in eachcylinder to act outwardly on the adjacent vane, means for supplyingoperating fluid under pressure to said cylinders to urge said plungersand vanes outwardly, and said fluid supply means including meansdefining fluid supply passage spaces confronting opposite ends of saidrotor in positions which register with the radially inward portions ofthe vane slots in the rotor as the slots move the coacting vanes throughsaid inlet zone of saidpumping space.

21. A rotary vane fluid power unit comprising, in combination, a rotor,housing means encasing said rotor and including means defining a camsurface encircling said rotor and defining therewith a fluid workingspace having fluid inlet and outlet zones, said rotor defining anannular series of vane slots opening outwardly through the periphcry ofthe rotor, a plurality of vanes slidably disposed position disposedoutwardly of the inner extremity of the slot, each vane having aradially inner portion shaped to overlap the adjacent rotor reinforcingelement for an extended distance when the vane is in its retractedposition, said housing means includingmeans for supplying fluid to theintake zone of said pumping space, said housing means including fluidoutlet means for releasing fluid from said outlet zone 'of said fluidworking space, said fluid outlet means including means defining outletpassage space confronting one end of said rotor, and said outlet passagespace having a position such that upon turning of said rotor todischarge fluid from said outlet zone of said working space each vaneslot carrying a vane through the outlet zone of the working space isbrought into an alinement with the passage space which alinement reachesa maximum value when the coating vane is passing through a medialportion of said fluid outlet zone and which is greatly reduced beforethe coacting vane passes beyond said fluid outlet zone.

22. A rotary vane fluid pump comprising, in combination, a rotor, meansdefining a cam surface encircling said rotor and defining therewith apumping space having fluid inlet and outlet zones, fluid supply meansfor supplying fluid to said pumping space at said inlet zone thereof,said rotor defining an annular series of vane slots opening outwardlythrough the periphery of the rotor; the bottom of each vane slot, asviewed in an axial section of the rotor, having a truncated triangularshape which tapers from opposite ends of the rotor in a radially outwarddirection to a flatted outer extremity centrally located axially betweenopposite ends of the rotor; a plurality of vanes slidably disposed insaid respective slots for engagement with said cam surface, each of saidvanes having a radially inner edge positioned on the vane and shaped toextend into adjacent relation to and to conform to the bottom of thecoacting slot when the vane is in a retracted position, and said fluidsupply means including means defining fluid supply passage spacesconfronting opposite ends of said rotor in positions which register withthe radially inward portions of the vane slots in the rotor as the slotsmove the coacting vanes through said inlet zone of said pumping space sothat fluid flows from said fluid supply spaces into the inner portionsof each vane slot passing through said inlet zone and is urged radiallyoutward by centrifugal force against the shaped inner edge of theadjacent vane to flow radially outward and axially inward along saidinner edge of the vane to fill the vane slot inward of the vane as thevane moves outwardly.

23. A rotary vane fluid pump comprising, in combination, a rotor, meansdefining a cam surface encircling said rotor and defining therewith apumping space having fluid inlet and outlet zones, fluid supply meansfor supplying fluid to said pumping space at said inlet zone thereof,said rotor defining an annular series of vane slots opening outwardlythrough the periphery of the rotor; the bottom of each vane slot, asviewed in an axial section of the rotor, having a shape whichprogressively narrows axially in a radially outward direction to anouter extremity centrally located axially between opposite ends of therotor; a plurality of vanes slidably disposed in said respective slotsfor engagement with said cam surface and for in and out radial movementsin the slots to follow said cam surface as said rotor rotates; each ofsaid vanes defining a radially inner edge having a shape, as viewed inan axial section of the rotor, that conforms generally to the shape ofthe bottom of the coacting slot; and said fluid supply means includingmeans defining fluid supply passage spaces confronting opposite ends ofsaid rotor in positions which register with the radially inward portionsof the vane slots in the rotor as the slots move the coacting vanesthrough said inlet zone of said pumping space so that fluid flows fromsaid fluid supply spaces into the inner portions of each vane slotpassing through said inlet zone and is urged radially outward bycentrifugal force against the shaped inner edge of the adjacent vanewhich directs the fluid axially inward along said inner edge of the vaneto fill the vane slot inward of the vane as the vane moves outwardly.

24. A rotary vane fluid power unit comprising, in combination, a rotordefining thereon two flat end face surfaces axially spaced apart andextending radially inward from the periphery of the rotor in concentricrelation thereto, a housing encasing said rotor and including meansdefining a cam surface encircling said rotor and defining therewith afluid working space having spaced zones for admitting and dischargingfluid, said rotor defining an annular series of outwardly open vaneslots spaced apart by intervening sectors of the rotor, a plurality ofvanes slidably mounted in said respective slots to extend outwardlytherefrom into engagement with said cam surface, each vane beingslidable in its slot between a retracted position and an extendedposition to effect continuous engagement of the outer maginal edge ofthe vane with said cam surface upon rotation of the rotor, each vanehaving an inner edge disposed within the corresponding vane slot for allpositions of the vane and being shaped to define in an inner portion ofthe vane a recess extending between opposite sides of the vane andextending outwardly in the vane from the inner extremity of the vane,said rotor including a plurality of rotor reinforcing elementscorresponding to said respective vane slots and occupying stationarypositions with respect to the rotor in which the reinforcing elementsextend radially outward for substantial distances into said recesses insaid respective vanes when the latter are in their fully retractedpositions, said rotor reinforcing elements each coacting with the twoadjacent rotor sectors to transmit forces therebetween to effect bymeans of the reinforcing elements a mutual reinforcement of saidintervening rotor sectors against applied bending loads, each of saidrotor reinforcing elements defining a cylinder opening outwardly towardthe opposing inner edge of the adjacent vane, a plunger slidably mountedin each of said cylinders to act outwardly on the inner edge of theadjacent vane, means including a pressure switching valve connectingsaid zones of said working space with said cylinders to supply fluidautomatically from the zone under the higher fluid pressure to eachcylinder to act on the plunger therein to urge the plunger and thecoacting vane outwardly, each vane having associated therewith meansproviding continuous communication for fluid between the inner and outeredges of the vane, the portion of each intervening rotor sector locatedradially inward of the radial positions of the inner edges of the fullyextended adjacent vanes being of solid construction that is imperviousto the passage of fluid therethrough between the adjacent slots andhaving a minimum axial width that is equal to the axial distance betweensaid flat end face surfaces on the rotor, and each of said flat end facesurfaces on the rotor extending continuously across the adjacent end ofeach rotor sector to the radially inner extremity thereof for the radialpositions of the adjacent portions of the fully extended vanes.

25, A rotary vane fluid power unit comprising, in combination, a rotordefining thereon two fiat end face surfaces axially spaced apart andextending radially inward from the periphery of the rotor in concentricrelation thereto, a housing encasing said rotor and including meansdefining a cam surface encircling said rotor and defining therewith afluid working space, said rotor defiing an annular series of outwardlyopen vane slots spaced apart by intervening sectors of the rotor, aplurality of vanes slidably mounted in said respective slots to extendoutwardly therefrom into engagement with said cam surface, each vanebeig slidable in its slot between a retracted position and an extendedposition to effect continuous engagement of the outer marginal edge ofthe vane with said cam surface upon rotation of the rotor, each vanehaving an inner edge disposed within the corresponding vane slot for allpositions of the vane and being shaped to define in an inner portion ofthe vane a recess extending between opposite sides of the vane andextending outwardly in the vane from the inner extremity of the vane,said rotor including a plurality of rotor reinforcing elementscorresponding to said respective vane slots and occupying stationarypositions with respect to the rotor in which the reinforcing elementsextend radially outward for substantial distances into said recesses insaid respective vanes when the latter are in their fully retractedpositions, said rotor reinforcing elements each coacting with the twoadjacent rotor sectors to transmit forces therebetween to effect bymeans of the reinforcing elements a mutual reinforcement of saidintervening rotor sectors against applied bending loads, the portion ofeach intervening rotor sector located radially inward of the radialpositions of the inner edges of the fully extended adjacent vanes beingof solid construction that is impervious to the passage of fluidtherethrough between the adjacent slots and having a minimum axial widththat is equal to the axial distance between said flat end face surfaceson the rotor, and each of said flat end face surfaces on the rotorextending continuously across the adjacent end of each rotor sector tothe radially inner extremity of the rotor sector from the radialpositions of the adjacent portions of the fully extended vanes.

26. A rotary vane fluid power unit comprising, in combination, a rotor,a housing encasing said rotor and including means defining a cam surfaceencircling said rotor, said cam surface being shaped and positioned inrelation to the periphery of said rotor to define therebetween a workingspace for fluid, said housing defining flow passages communicating withsaid working space at spaced positions therealong, said rotor definingan annular series of vane slots therein opening outwardly through the'periphery of the rotor and being separated by intervening sectors ofthe rotor, an annular series of circumferentially spaced vane unitscorresponding in number to and being formed in part by said respectivevane slots, each vane unit including a vane slidably disposed in itscorresponding slot in said rotor between a retracted position and afully extended position to effect continuous engagement of the outeredge of the vane with said cam surface upon rotation of the rotor, thevane of each vane unit having an inner edge disposed within thecorresponding vane slot for all positions of the vane and being shapedto define in an inner portion of the vane a notch extending betweenopposite sides of the vane and extending outwardly in the vane from theinner extremity of the vane, said rotor including a plurality of rotorreinforcing elements corresponding to said respective vane slots andoccupying stationary positions with respect to the rotor in which thereinforcing elements extend radially outward for substantial distancesinto said'recesses in said vanes of said respective vane units when thevanes are in their retracted positions, said rotor reinforcing elementseach coacting with the two adjacent rotor sectors to transmit forcestherebetween to effect by means of the reinforcing elements a mutualreinforcement of said intervening rotor sectors against applied bendingloads, the portion of each intervening rotor sector located radiallyinward of the radial positions of the inner edges of the fully extendedadjacent vanes being of solid construction that is impervious to thepassage of fluid therethrough between the adjacent slots and having aminimum axial width that is at least substantially equal to the maximumaxial width of the portion of each adjacent vane that extends outwardlyfrom the periphery of the rotor when the vane is fully extended, eachvane' unit defining first and second vane biasing surfaces associatedwith the vane of the unit and being continuously exposed by the vaneunit to the pressure of fluid in the interspace adjacent the vanebetween said cam surface, said first biasing surface for each vane unitbeing oriented so that the force thereon of fluid pressure urges thecorresponding vane inwardly, said second biasing surface of each unitbeing oriented so that the force of fluid pressure thereon urges thecorresponding vane outwardly, each vane unit defining a third biasingsurface associated with the corresponding vane and oriented so that theforce of fluid pressure on said third surface urges the vane outwardly,each vane unit including means associated therewith to isolate saidthird biasing surface thereof from direct communication with said secondbiasing surface of the unit, means associated with each unit forsupplying to said third biasing surface thereof fluid under highpressure from a high pressure portion of said working space for fluid,each vane unit including spring means stressed to urge the correspondingvane outwardly in its slot, said spring means for each vane having amovable power applying portion which acts on the vane and moves in andout with the vane as the vane moves in and out in its slot, and saidspring means for each vane having a support portion which reacts on therotor to transmit thereto the reaction of the adjacent vane on thespring means and which ,is stationary with respect to the rotor so thatthe spring means is flexed and stores energy upon inward movement of thevane and subsequently releases energy by relaxation to extend the vane.

References Cited by the Examiner UNITED STATES PATENTS 732,109 6/ 1903Patterson 103--136 2,752,851 7/1956 Garner et a1 l03'136 2,832,1994/1958 Adams et al 103136 2,832,293 4/1958 Adams et al 103,136 3,103,8939/1963 Henn-ing et al.. 103136 SAMUEL LEVINE, Primary Examiner.

DONLEY I. STOCKING, Examiner.

R. M. VARGO, Assistant Examiner.

UNITED STATES PATENT OFFICE CERTIFICATE OF CORRECTION Patent No 3 257,958 June 28 1966 Cecil E. Adams et a1.

It is hereby certified that error appears in the above numbered patentrequiring correction and that. the said Letters Patent should read ascorrected below.

Column 2, line 39, for "inwardly" read H inward column 3, line 25, for"but" read and column 4, line 11, for "end" read ends column 7, line 29,for "efftctive" read effective column 10, line 7 for "af'luid" read afluid column ll, line 15, for "theinner" read the inner line 32, for"refernce" read reference line 73, for "valve" read vane column 12, line2, for "liquid" read fluid line 38, for "van" read vane line 49, for"surface" read surfaces line 60, for "throtting" read throttling line70, for "engagemednt" read engagement lines 72 and 73, for "coating"read coacting column 13, line 38, after "vane" insert edge line 47 for"check" read cheek line 51, for "port" read ports column 14, line 38,before "reference" insert same line 55, after "vane" insert as the vanecolumn 15, line 3 for "betwen" read between H line 41 for "thereupon"read thereon column 17, line 59, for "vanes" read vane column 19, line45, after "from" insert the column 20, line 68, for "Vance" read vanecolumn 21, line 71, after "vanes" insert being column 22, line 42, after"flowing" insert communication from opposite ends of the rotor throughthe inner portion of the vane slot to said outwardly offset medialportion of the inner edge of the vane column 25, line 74, for "elementread elements column 26, line 69, for "coating" read coacting column 28,line 42, for "defiing" read defining line 47 for "beig" read beingcolumn 30, line 5, after "between" insert said rotor and Signed andsealed this 1st day of August 1967.

(SEAL) Attest:

EDWARD M.FLETCHER,JR. EDWARD J BRENNER Attesting Officer Commissioner ofPatents

1. A ROTARY VANE FLUID POWER UNIT COMPRISING, IN COMBINATION, A ROTOR, A HOUSING ENCASING SAID ROTOR AND INCLUDING MEANS DEFINING A CAM SURFACE ENCIRCLING SAID ROTOR, SAID CAM, SURFACE BEING SHAPED AND POSITIONED IN RELATION TO THE PERIPHERY OF SAID ROTOR TO DEFINE THEREWITH A WORKING SPACE FOR FLUID, SAID HOUSING DEFINING FLOW PASSAGES COMMUNICATING WITH SAID SPACE AT SPACED POSITIONS THEREALONG, SAID ROTOR DEFINING AN ANNULAR SERIES OF VANE SLOTS THEREIN OPENING OUTWARDLY THROUGH THE PERIPHERY OF THE ROTOR AND BEING SEPARATED BY INTERVENTING SECTORS OF THE ROTORS, A PLURALITY OF VANES MOUNTED IN SAID RESPECTIVE SLOTS TO EXTEND FROM THE PERIPHERY OF THE ROTOR INTO CONTINUOUS ENGAGEMENT WITH SAID CAM SURFACE, EACH VANE BEING SLIDABLE IN ITS SLOT BETWEEN A FULLY EXTENDED POSITION AND A FULLY RETRACTED POSITION TO EFFECT CONTINUOUS ENGAGEMENT OF THE OUTER MARGINAL EDGE OF THE VANE WITH SAID CAM SURFACE UPON ROTATION OF THE ROTOR, EACH VANE HAVING AN INNER EDGE DISPOSED WITHIN THE CORRESPONDING VANE SLOT FOR ALL POSITIONS OF THE VANE AND BEING SHAPED TO DEFINE IN AN INNER PORTION OF THE VANE A NOTCH EXTENDING BETWEEN OPPOSITE SIDES OF THE VANE AND EXTENDING OUTWARDLY IN THE VANE FOR AN EXTENDED DISTANCE WITHIN THE INNER EXTREMITY OF THE VANE, PLUGS DISPOSED WITHIN SAID RESPECTIVE VANE FOR SUBSTANTIAL DISTANCES OUTWARDLY OF THE COACTING VANES FOR SUBSTANTIAL DISTANCES OUTWARDLY OF THE POSITIONS OCCUPIED BY THE INNER EXTREMITIES OF THE RESPECTIVE VANES WHEN THE RESPECTIVE VANES ARE MOVED INTO THEIR RETRACTED POSITIONS IN THE SLOTS BY SAID CAM SURFACE, SAID PLUGS EACH BEING SHAPED AND DIMENSIONED TO FIRMLY ENGAGE SIMULTANEOUSLY THE TWO OPPOSING SIDE SURFACES OF THE ASSOCIATED SLOT TO EFFECT BY MEANS OF THE PLUGS A MUTUAL REINFORCEMENT OF SAID INTERVENING ROTOR SECTORS, THE PORTION OF EACH INTERVENTING ROTOR SECTOR 